We only have duty to save humans as much as it in our power. In other words: as much as practicable.I don't know. Thankfully, I have never been placed in that situation and likely never will.
I would need more information such as how likely is it that mom would die. What could be done to save her if fallopian tubes exploded. How much time would she have to receive care, etc.
Even then, it would be a gut wrenching decision.
No point in getting rescue team to need rescue.
If you did all you could, you have done your duty.
Since ectopic pregnancy is practically death sentence for mother and we can't do nothing for baby, only reasonable choice is to save mother. This is only we could do. Baby is, sorry to say, Lord's problem.